/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.lucene.search;

import java.util.concurrent.atomic.LongAccumulator;

/** Maintains the maximum score and its corresponding document id concurrently */
final class MaxScoreAccumulator {
  // we use 2^10-1 to check the remainder with a bitwise operation
  private static final int DEFAULT_INTERVAL = 0x3ff;

  // scores are always positive
  final LongAccumulator acc = new LongAccumulator(Math::max, Long.MIN_VALUE);

  // non-final and visible for tests
  long modInterval;

  MaxScoreAccumulator() {
    this.modInterval = DEFAULT_INTERVAL;
  }

  void accumulate(long code) {
    acc.accumulate(code);
  }

  long getRaw() {
    return acc.get();
  }
}
